For a number of years, ostomy appliances have been commercially available with plastic coupling rings that mate together in a manner similar to the rims of plastic food containers, photographic film containers, and the like. With one of the rings mounted upon the collection pouch and the other secured to a faceplate adhered to the wearer about the stoma opening, the wearer may couple and uncouple the rings for purposes of venting, draining, or replacing the pouch, or for any other reason, without breaking the adhesive seal between the faceplate and the wearer's skin. Detachability of the pouch is therefore achieved while at the same time providing a faceplate that may remain adhered to the wearer for an extended period that suits his/her comfort and convenience.
U.S. Pat. No. 4,232,672 discloses a pair of plastic coupling rings used in the manner described above. Like the mating rims of other types of containers or closures, one ring is provided with a channel, and the other ring has a deformable insert element receivable in that channel. U.S. Pat. No. 4,170,231 similarly illustrates an ostomy appliance having a pair of flexible plastic coupling rings for detachably supporting the pouch upon the faceplate. Other patents of interest are U.S. Pat. Nos. 3,817,420, 3,759,415, France Pat. No. 2,316,142, and Sweden Pat. No. 351,610.
Regardless of the details of construction, flexible plastic coupling rings used for ostomy appliances must be capable of providing a fluid-tight seal and must also provide an interlock that is tight enough to avoid unintentional detachment of the pouch from the faceplate. For such purposes, the mating thermoplastic rings must have wall thicknesses and/or compositions that provide the rings with sufficient stiffness to insure a secure coupling. Unfortunately, the advantages that such stiffness provide are offset by patient discomfort not only during the wearing of the appliance but also when coupling or uncoupling is desired. To secure the parts together, the pouch ring must be pushed into tight locking engagement with the faceplate ring, and the application of such force against the faceplate and the tender peristomal skin below it may cause considerable wearer discomfort. Removal presents a similar problem, since the pulling force needed to separate the rings may be transmitted to the faceplate to the peristomal area causing patient discomfort and, at least in some instances, causing the faceplate ring to pull way from the body, increasing the possibilities of subsequent leakage and/or reducing the wearing time for the appliance. If, in order to reduce discomfort associated with attaching the coupling rings, a patient uses only minimal force to couple such rings, there is a risk that the mechanical seal will be insufficient to prevent the leakage of odors, fluids, or solid materials, and may even be insufficient to retain the collection pouch in place.
Accordingly, it is a main object of this invention to provide an improved coupling which permits the wearer (or attendant) to attach and detach the coupling rings without the transmission of any appreciable pulling or pushing forces to the peristomal (or periwound) area. Since the discomforts associated with attachment and detachment are eliminated or at least greatly reduced, the chances that a user might incompletely join the coupling rings are also reduced.
Another important aspect of this invention lies in providing a secure but disconnectable coupling comprising a pair of semi-rigid coupling rings which, despite their stiffness, allow full conformity of the faceplate to the peristomal area, even when the wearer bends, turns, and moves about. Such a construction virtually eliminates the possibility that wearer movement might result in unintentional uncoupling of the plastic rings from each other. Since the coupled rings do not interfere with limited flexing and deforming of the faceplate, the construction of this invention may be used effectively with patients who, because of obesity or awkward stoma location, would be unable to wear current appliances with detachable plastic coupling rings. Distortions of the faceplate that would be resisted or prevented by the coupling rings of prior constructions are absorbed by the floating interconnection of this invention, thereby avoiding the transmission of stresses that might otherwise result in unintentional uncoupling of the rings, or a peeling away of the faceplate from the patient, or an incomplete attachment of the faceplate to the patient in the first instance.
Briefly, an ostomy appliance embodying this invention includes a pair of semi-rigid coupling rings detachably connectable to each other, one of the rings (referred to as the first ring) being secured to a flexible collection pouch so that the opening of the ring communicates with the pouch's interior, and the other (second) ring being mounted upon a highly flexible faceplate adapted to be adhesively secured to the peristomal surface of a wearer's body. The second coupling ring is mounted upon the faceplate by means of a flexible and resilient thermoplastic web. The web is annular in configuration, having an outer edge portion secured to the periphery of the second ring and an inner edge portion secured to the faceplate about the aperture thereof. Because the web is formed from a relatively thin, resilient, and deformable plastic film, it permits limited movement of the second ring in generally axial directions with respect to the faceplate, thereby facilitating attachment of the two coupling rings, or detachment of those rings, without the transmission of pushing or pulling forces to the faceplate and to the peristomal area to which it is secured. In addition, the flexible and resilient annular web permits conformity of the faceplate to a wearer's body without objectionable resistance from the relatively stiff coupling rings. The resilient web thereby provides a non-rigid interconnection between a pliable or deformable faceplate and the coupling ring assembly, allowing the ring assembly to float to a limited extent with respect to the faceplate, and vice versa.
In the embodiment disclosed, the second ring (i.e., the one mounted upon the faceplate) includes a radially and circumferentially extending annular flange portion having a bead extending about the outer perimeter thereof. Additionally, the flange may be provided with a slight but definite curvature (when viewed in radial section) with the convex surface of the flange facing towards the faceplate, so that when the parts are in untensioned or undistorted condition, the bead of the flange is normally spaced a slight distance from the faceplate. In either event, a user may easily and quickly insert his/her fingers between the flange and faceplate to brace the flange and the second coupling ring when the two coupling rings are to be latched together. Similarly, when the rings are to be disconnected, the second ring may be easily gripped by its enlarged flange portion and held in place while a tab-equipped portion of the first ring (the ring connected to the collection pouch) is pulled away.
The flexible and resilient annular web is secured to the beaded periphery of the second coupling rings's flange portion. Such web and other components are preferably formed of thermoplastic materials and heat-sealed to each other.
Other features, advantages, and objects of the invention will become apparent from the specification and drawings.